Rotary pump



April 12, 1932.

LE ROY A.- WESTMAN ET AL ROTARY PUMP Filed May 26, 1950 3 Sheets-Sheet INVENTOR LERUY m wssm/m GLENN B- cmmn/v BY= MAJ L ATTORNEY April 1932- LE ROY A.-.WESTMAN ET AL 1,353,391

ROTARY PUMP Filed May 26, 1930 s Sheets-Sheet 2 April 12, 1932. LE ROY A, WESTMAN ET AL 1,353,391

' ROTARY PUMP Filed May '26, 1930 I 3 Sheets-Sheet 3 mVEN'roR zzkar fiwssmalv ELENN 3 elm/Wm 'WM MMT ATTO RN EY Patented Apr L 12,-1932 UNITED STATES ATEN orrrcr:

LE ROY A. WES'I'MAN AND GLENN B. CARE, CLEVELAND, OHIO noun; run

Application fled Kay 26, 1930. Serial Io. 458,518.

Our invention relates to an imprpvement in rotary pumps, particularly pumps in which reciproca 1e pistons are used within a rotatable cylinder in operating conjunction with inlet and outlet ports in the pump body. In general our object is to eliminate objectionable wear, leakage, and loss in efficiency in a pump of that type, all as hereinafter more specifically shown, described and claimed.

In the accompanying drawings, Fig. 1 is an end view and Fig. 2 is a side elevation, of a pump embodying our invention. Fig. 3 is a sectional view longitudinally through the pump, and Figs. 4 and 5, are cross sections thereof on lines 4- 1, and 5-5, respectively,

of Fig. 3. Fig. 6 is a sectional view horizontally through the pump body, showing the shaft and rotatable cylinder therein in elevation. Fig. 7 is a perspective view of the cylinder, and Fig. 8 an end view thereof. Fig. 9-is a side elevation of the eccentric shaft, and

Fig. 10 a perspective view of one of the pis-- tons.

The pump comprises a main body 2 which is cylindrical in part and secured at one end to a head 3 having a supporting extension 4. The opposite end of said body is provided with a removable closure plate 5 having a central boss 6 within which one end of a power shaft 7 has rotatable bearing. Shaft 7 extends through head 3 and'a packing gland 8 therein, the power to rotate the shaft being applied to the protruding end 9 of the shaft,

either by gear or pulley, not shown. Body 2 is formed with a circular-working chamber 10 extending from one flat end to the other where closed by head 3 and plate 5, and shaft 7 is eccentrically related to the axis of this chamber. Shaft 7 is also provided with a pair of circular eccentrics 11 and 12, respectively, in crank relation. As shown, the axes of these eccentrics are one-hundred and eighty degrees apart, thus placing them in the same plane on oppositesides of the axis of the shaft. A pair of pistons 14 and 15, respectively, are coupled rotatably to said eccentrics 11 and 12, and these pistons are confined with in straight slots or channels 16and 17, respectively, extending diametrically of a rotatable cylinder or rotor member 18 but in planes at right angles to each other. A central division wall 19 within cylinder 18 separates the channels 16 and 17, and shaft 7 extends through a circular opening 20 of suflicient size in this division wall to permit the cylinder to rotate freely without engaging the shaft, which is eccentrically positioned in respect to the axis of the cylinder.

As shown, the side walls of the straight channel are flat sided and the pistons are of corresponding shape and have a sliding fit therein. However, the op site ends of each piston are partly recess or flattened and formed with rounded ribs 21, to provide a small space within which sediment, chips 6 or extraneous matter may be picked up and from thence discharged during the rotatable "movements of the cylinder without injury to the working parts.

In the present machine a cylindrical sleeve 22 is shrunk or forced tightly over the solid cylinder 18, thereby enclosing the opposite ends of the diametrical channels 16 and 17, except where short circumferential slots 23, 24, 25, and 26, are provided in the sleeve. These slots are preferably narrow and also of slightly less length than the width of the piston and the channel in which the piston reciprocates, see Figs. 3 and 5. The slots are also preferably locatedinwardlyfrom' the ends of the cylinder closely adjacent the inner wall of each channel where they may be brought into register with a pair of inlet and out at ports 27 and 28, respectively, located centrally on opposite sides of pump 35 body 2, see Figs. 4 to 6. Separate supply and discharge pipes 29 and 30, respectively, are connected to the top of body 2'in open communication with ports 27 and 28, and a by-pass opening 31 is formed in a division wall 32 between the inlet and outlet sides of the pump so that the fluid may circulate within the pump itself should the flow of fluid through the discharge pipe 30 be in-' F terrupted or cut off. Normally, the by-pass opening is closed by a spring-pressed valve v33 seated against one'side of wall 32. A tubular member 34 is screwed to body 2 to support the valve and its spring 35, and an adjustmg screw 36 protr des through the outer end of this member to permit the tension of the spring to be adjusted to may given pressure conditions in the outlet si e of the pump. Member 34 and the valve parts associated therewith may also be transferred to the opposite side of the pump upon removing a screw-plug 37 thereat opposite a second valve seat 38 in division wall 32. Shifting of these parts permits the pump to be reversely rotated, and the fluid pumpe in the opposite direction.

In operating the pump the eccentric shaft and the eccentrics thereon reciprocate the two pistons within their respective channels or working spaces, and at the same time revolve the cylinder and its slotted sleeve within the pump body. Two revolutions of the shaft produce one revolution of the cylinder and its sleeve, and during each single revolution of the cylinder each piston functions to draw in a charge and, to expell a charge. The successive pumping operations of the two pistons provide a continuous flow or compression of fluid at the discharge side of the pump, and so there is a constant pressure exerted from that side only on the moving parts of the pump. The pistons reciprocate in planes at right angles to each other, and are balanced in respect to each other, but nevertheless the cylinder and chamber walls of a rotary machine of this type have been found to wear unevenly because the working spaces or areas of the piston are directly exposed to equally lar working areas in the circular wall of t e cylinder chamber in body 2. .To overcome such unequal wear and leakage, and to promote smooth running,'long life, and a higher efliciency, we have encased the channeled cylinder within a separate sleeve and formed narrow slots in this sleeve at the opposite ends of the working channels or spaces in the cylinder. As a result the pistons revolve with the cylinder and sleeve, and reciprocate within the channels with their working areas opposed to the relatively stationary surface or area at the inner side of the sleeve, and only a small area of thechamber wall in body 2 equivalent to the width of the narrow slot in the sleeve is exposed to the working area of the piston. Except for the narrow slots in the sleeve the rotatable bearing for the cylinder is uniformly equal to the full length and. diameter of the cylinder, and the roduction of a smoothly-running and close y-fitting cylinder in the present ump' is also simplified by making the cylin er in two parts, that is, with a channeled body and a sleeve. The degree of eccentricity of shaft 7 to'the axis of cylinder 18 is-such that the center of each eccentric on the shaft travels in an orbit in touch with the axis of the cylinder, thereby permitting the shaft to reciprocate the pistons within the cylinder and to revolve the cylinder freely within havin a body havin a chamber and mlet and outlet ports, a cy inder rotatably confined with in said chamber having straight channels diametrically thereof,- a sleeve tightly fixed to said cylinder having narrow circumferential slots at the opposite ends of said channels close to the central portion of said body adapted to communicate with said ports, pistons having recessed end areas reciiproca- 1y confined within said channels, an a rotatable shaft eccentrically positioned within said chamber having eccentrics rotatably coupled to said pistons.

2. A rotary pump, comprising a body hav-- ing a circular chamber with inlet and outlet ports on opposite sides thereof and separate chambers at the top communicating with said inlet and outlet ports, said chambers being separated by a wall having a assa c with valve seats at opposite sides of the wa l, a' rotatable cylinder within said circular chamber having piston chambers diametrically arranged and angularly related with respect to each other, the circular walls of said cylinder having narrow, circumferential slots communicating with the ends of said "piston chambers, reciprocable pistons recessed end working faces within said piston chambers, and. a rotatable shaft eccentrically positioned within said chamber having eccentrics rotatably coupled to said pistons.

In testimony whereof we aflix our signatures.

LE ROY A. WESTMAN. GLENN B. GARMAN. 

